Nature and nurture go hand in hand, say scientists who study obesity and diabetes. In this month's issue of Genome Research, Edward Leiter and colleagues (The Jackson Laboratory) report that an animal's 'maternal environment' acts together with genetics to increase the risk of obesity and obesity-related diabetes.
Type II diabetes particularly afflicts obese individuals. Numerous genes and environmental factors, like sedentary lifestyle, interact to produce a predisposition for diabetes (diabesity), making it difficult to tease out individual suspects. In the current report, Leiter and colleagues perform an ingenious experiment to identify specific gene-environment interactions affecting diabesity.
The researchers crossed two strains of mice, one obese and one lean, and looked for unique DNA sequences that correlate with diabesity in the descendants. Leiter and colleagues identified several gene locations involved in different aspects of fat deposition and diabetes risk. Furthermore, the effects of these genes depended on whether the nursing mother was obese or lean; mice with genetic predisposition for diabesity were less obese if nursed by a lean foster mother. The researchers suggest that factors in mother's milk may act in combination with genetic heritage to trigger obesity and consequent diabetes, a finding with potential health implications for obese human populations.
Contact (author):
Edward Leiter
The Jackson Laboratory
Bar Harbor, Maine 04609
USA
Ehl@jax.org
Genome Research